Vehicle braking system comprising brake rigging, and vehicle equipped with such a system

ABSTRACT

A braking system for a vehicle includes a brake rigging and a service and/or parking brake designed to act on at least one braking member of the vehicle via the brake rigging. The braking system has at least one device with at least one lining support and at least one lining that is mechanically attached to the at least one lining support. The device comprises at least two bearing zones in contact with the at least one braking member, and at least one recessed zone located between the two bearing zones.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage entry of International PatentApplication No. PCT/EP2020/070888 (filed 23 Jul. 2020), which claimspriority to French Patent Application No. 1908510 (filed 26 Jul. 2019),French Patent Application No. 1908512 (filed 26 Jul. 2019), and FrenchPatent Application No. 1911666 (filed 18 Oct. 2019), the entiredisclosures of which are incorporated herein by reference.

BACKGROUND Technical Field

The inventive subject matter concerns the field of vehicle brakes. Moreparticularly, the inventive subject matter concerns a braking system fora rail vehicle having brakes with at least one lining, provided with abraking linkage and with a service brake and/or parking brake configuredto act on the braking members of the vehicle (for example, such as brakedisks) via the braking linkage.

Discussion of Art

The vehicles referred to as having brakes with at least one lining aregenerally equipped with braking systems having service brake and/orparking brake cylinders, comprising a piston movable under the effect ofa fluid under pressure. Movement of the piston actuates a brakinglinkage and drives a braking action (such as the clamping of a brakedisk) by the lining of that linkage.

Such a braking system is mounted on the vehicle to be in contact withthe brake disks or the wheels. In particular, the braking system may bemechanically connected to a bogie, to an axle fastened to the bogie, orto another device like the drive motor or the gearbox also mounted onthe bogie.

The braking action gives rise to braking forces which may be transmittedto the mounting to which the braking system is mechanically connectedvia the braking linkage. These forces may generate deformations, or atleast movements, of the braking linkage relative to the brake disk ofthe vehicle, thereby giving rise to irregular wear of the lining.

BRIEF DESCRIPTION

The inventive subject matter concerns a braking system for a vehiclehaving brakes with at least one lining. The braking system includes animproved braking linkage, while being simple, convenient and economical.

According to a first aspect, the inventive subject matter relates to arail vehicle braking system, comprising a braking linkage and a servicebrake and/or parking brake configured to act on at least one brakingmember of the rail vehicle via the braking linkage. The linkage isprovided with at least one device having at least one lining mountingand at least one lining mechanically connected to the at least onelining mounting. The device comprises at least two bearing regions forbearing on the at least one braking member and at least one set backregion located between the two the bearing regions.

In other words, the device of the braking linkage (which contacts thebraking member of the vehicle, for example in particular a brake disk)is provided with a bearing surface referred to as being discontinuous,with only the bearing regions which enable forces to be transmitted tothe brake disk. This enables the transmission of the forces to the brakedisk to be distributed. In particular, the bearing regions and the setback regions can be provided on the braking linkage device according tothe type of braking system and/or the use of the rail vehicle. Forexample, the arrangement of the braking linkage of which the form, thearrangement and/or the materials of the lining mounting and/or of thelinings, the fact of whether the braking linkage is a parking brake orelse a service brake, the type of vehicle (tram, subway train,high-speed train, etc.) and/or the load of the vehicle, the journey madeby the vehicle, and/or the type of braking member (diameter, thickness,material of the disk) may be parameters for determining the bearing andset back regions.

The placing of the bearing and set back regions may thus bepredetermined, for example by trials in advance. Such bearing and setback regions are configured to distribute the transmission of the forcesover the braking member. These regions are quite different from anyregions for fastening the linings onto the lining mounting, these latternot being configured to distribute the transmission of the forces overthe braking member.

Features according to the inventive subject matter that are preferred,simple, convenient and economical are presented below.

The system may comprise at least two linings mechanically connected tothe lining mounting, at least one the bearing region being locatedfacing opposite the respective lining. The at least two bearing regionsand the at least one set back region may be provided on the at least onelining mounting. This, in particular, enables so-called standard liningsto be used. The at least two bearing regions and the at least one setback region may be provided on the at least one lining.

The device may comprise a plurality of the bearing regions between whichare formed the set back regions. The at least one lining mounting and/orthe at least one lining may have a longitudinal general orientation anda transverse general orientation, with the bearing and set back regionssucceeding each other in the longitudinal general orientation. At leastone the bearing and/or set back region may extend fully or only partlyalong the transverse general orientation. The bearing and set backregions are provided substantially symmetrically relative to atransverse central axis of the device. This axis may for exampleconstitute a median axis of the braking member of the rail vehicle.

The braking linkage may be provided with at least one lever extendingfrom the service brake and/or parking brake to the device. The at leastone lever to may be mechanically connected to the at least one liningmounting on an attachment region thereof which is located away from theat least one lining and which is at most 35 millimeters (mm) from atransverse central axis of the device.

The attachment region may be located between approximately 0 and 35 mmfrom the transverse central axis of the device. The attachment regionmay extend in a longitudinal general orientation of the device and overa length comprised between approximately 15 mm and approximately 75 mm.The attachment region may extend uninterruptedly on opposite sides ofthe transverse central axis of the device. The at least one attachmentregion may extend interruptedly on opposite sides of the transversecentral axis of the device.

The system may comprise at least one force transmission link membermechanically connected at a first end to a mounting of the vehicle andat a second end, which is an opposite end to the first end, to the atleast one lining mounting, in immediate proximity to the attachmentregion of the at least one lever. The at least one force transmissionlink member may be substantially L-shaped, or S-shaped. The at least oneforce transmission link member may extend substantially in a same planeas that in which extends the at least one lever. The at least one forcetransmission link member may be mechanically connected by pivotalconnections respectively to the vehicle mounting and to the at least onelining mounting. The at least one force transmission link member mayhave an added functional clearance at its second end where it isconnected to the at least one lining mounting. The at least one forcetransmission link member may be connected via a rotary joint to the atleast one lining mounting. The at least one force transmission linkmember may be connected to the at least one lining mounting via apivotal shaft pivoting in an aperture of considerably greater diameterthan that of the pivotal shaft, or in an oblong aperture.

According to a second aspect, the inventive subject matter also relatesto a rail vehicle comprising at least one braking member (for example inparticular a brake disk) and at least one rail vehicle braking system asdescribed above, which is configured to act on the at least one brakingmember.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure of the inventive subject matter will now be continuedwith the description of embodiments, given below by way of illustrativeand non-limiting examples, with reference to the accompanying drawings.

FIG. 1 is a diagrammatic and partial illustration of a vehicle brakingsystem provided in particular with a service brake, a parking brake, andwith a control and actuation unit.

FIG. 2 is a partial and diagrammatic representation of the systemillustrated in FIG. 1 mechanically connected to an axle for a bogie of avehicle comprising such a vehicle braking system.

FIG. 3 is a diagrammatic representation of a lining mounting accordingto a first embodiment of the vehicle braking system of FIG. 1, whichlining mounting is mounted facing opposite a first face of a brake diskalso illustrated in FIG. 1.

FIG. 4 is a cross section view on IV-IV of FIG. 3;

FIG. 5 is a diagrammatic representation of a contact face of the liningmounting illustrated in FIG. 3.

FIG. 6 diagrammatically illustrates linings facing opposite the firstface of the brake disk, which linings are provided to be carried by thelining mounting.

FIG. 7 is a similar view to that of FIG. 4, showing a first variantembodiment of the lining mounting.

FIG. 8 is a similar view to that of FIG. 5, showing the first variantembodiment of the lining mounting.

FIG. 9 is a similar view to that of FIG. 6, the linings being mounted onthe first variant embodiment of the lining mounting.

FIG. 10 is a similar view to that of FIG. 8, showing a second variantembodiment of the lining mounting.

FIG. 11 is a similar view to that of FIG. 9, the linings being mountedon the second variant embodiment of the lining mounting.

FIG. 12 is a similar view to that of FIG. 10, showing a third variantembodiment of the lining mounting.

FIG. 13 is a similar view to that of FIG. 11, the linings being mountedon the third variant embodiment of the lining mounting.

FIG. 14 is a similar view to that of FIG. 3, showing a lining mountingaccording to a second embodiment of the rail vehicle braking system ofFIG. 1.

FIG. 15 is a cross section view on XV-XV of FIG. 14;

FIG. 16 is a diagrammatic representation of a contact face of the liningmounting illustrated in FIG. 14.

FIG. 17 is a similar view to that of FIG. 6.

FIG. 18 is a similar view to that of FIG. 14, showing a forcetransmission link member mechanically connected to the lining mounting.

FIG. 19 is a similar view to that of FIG. 15, with addition of the forcetransmission link member.

FIG. 20 is a very diagrammatic view showing a lining mounting accordingto a third embodiment of the vehicle braking system.

DETAILED DESCRIPTION

FIG. 1 diagrammatically represents a vehicle braking system 1 for avehicle having a brake with linings. This is a rail vehicle brakingsystem structurally of the type described in European patent applicationEP 2 826 684. The vehicle braking system 1 comprises a body 2 forming acylinder of both a service brake 6 and a parking brake 7, a control andactuation unit 3 configured to manage the operation of the service brake6 and of the parking brake 7, a conveyance network of pneumatic pipesthat is connected to the body 2 and to the control and actuation unit 3,and a braking linkage 4 mechanically linked to the body 2.

The body 2 has the form of a generally closed envelope. The servicebrake 6 comprises a service brake piston 8 movable relative to the body2 in a first axial direction, and a thrust rod 9 also movable relativeto the body 2 in a second axial direction perpendicular to the firstaxial direction. Together with the body 2 the braking piston 8 delimitsa service brake pressure chamber 13.

The braking piston 8 has two sides including a first side 17 configuredto act on the braking linkage 4 via the thrust rod 9 and a second side18 which is an opposite side to the first side 17 and which is turnedtowards the service brake pressure chamber 13. The service brake 6further comprises a notched rod 21 fastened to the second side 18 of thebraking piston 8. This notched rod 21 extends longitudinally in thefirst axial direction. The braking piston 8 is configured to move in thebody 2 while maintaining the service brake pressure chamber 13relatively fluid-tight thanks to a membrane 14, for example formed by aseal, disposed between that braking piston 8 and inside edges of thebody 2.

The service brake 6 may further comprise a wedge part 10 fastened to thefirst side 17 of the braking piston 8. This wedge part 10 may have atriangular section and be configured to cooperate with a set of rollingbearing stops 11, of which one of the rolling bearing stops may belinked to the body 2 while the other of the rolling bearing stops may belinked to the thrust rod 9. This thrust rod 9 may be provided with awear adjuster configured to compensate for the wear of the linings ofthe brake 5 in order to avoid reduction of the braking force byexcessive play (further to wear of the linings).

The service brake 6 may comprise a spring 12 disposed around the thrustrod 9, between the rolling bearing stop which is linked to the latterand an inside edge of the body 2. This spring 12 is configured to returnthe stop which is linked to the thrust rod 9 against the wedge part 10.The service brake 6 may comprise a first aperture 15 formed in the body2 and configured to enable the movement of the thrust rod 9 through thatfirst aperture 15. The service brake 6 may comprise a second aperture 16formed in the body 2 and opening into the service brake pressure chamber13. The service brake pressure chamber 13 is connected here by a firstsupply pipe 72 of the conveyance network of pneumatic pipes, moregenerally called brake pipe, which pipe is connected at the location ofthat second aperture 16, to a source of supply of pneumatic pressureagents (not shown).

The body 2 comprises a cavity 27 situated against the service brakepressure chamber 13 and in which is disposed the parking brake 7. Theparking brake 7 comprises a blocking device formed by a blocking finger20 movable relative to the body 2 and extending in the second axialdirection. The parking brake 7 comprises a holding piston 23 movablerelative to the body 2 and with the latter delimiting a parking brakepressure chamber 25. This holding piston 23 has two sides, respectivelya first side 31 on which is attached the blocking finger 20 and which isturned towards the parking brake pressure chamber 25, and a second side32 which is an opposite side to the first side.

The parking brake 7 comprises a spring member 24 disposed between thebody 2 and the second side 32 of the holding piston 23. This springmember 24 is configured to act on that holding piston 23 and thereforeon the blocking finger 20. The holding piston 23 and the spring member24 may form a movable actuating device of the parking brake 7. Theholding piston 23 is configured to move in the body 2 while maintainingthe parking brake pressure chamber 25 relatively fluid-tight thanks to amembrane disposed between that holding piston 23 and the inside edges ofthe body 2. The parking brake 7 comprises a third aperture (not shown)formed in the body 2 and opening both into the parking brake pressurechamber 25 and into the service brake pressure chamber 13, which thirdaperture is configured to enable the movement of the blocking finger 20through that third aperture. The relative sealing between the parkingbrake pressure chamber 25 and the service brake pressure chamber 13 isensured by the presence of a seal 33 disposed at the interface betweenthat third aperture and the blocking finger 20.

The parking brake 7 comprises a fourth aperture 28 formed in the body 2and opening into the parking brake pressure chamber 25. The parkingbrake pressure chamber 25 may be connected here by a second supply pipe71 of the conveyance network of pneumatic pipes, also called parkingbrake pipe, which is connected at the location of that fourth aperture28, to the source of supply of pneumatic pressure agents 73 (visible inFIG. 2) via the unit 3.

The parking brake 7 comprises an unlocking part 29 to deactivate theparking brake 7. The unlocking part 29 may for example be attached onthe second side 32 of the holding piston 23 and open to the outside ofthe body 2 through a fifth aperture (not shown) provided in that body 2and opening into the cavity 27. The unlocking part 29 is accessible tobe manipulated from outside the body 2 if required. The unlocking part29 may be connected to an indicator device provided to indicate a stateof the parking brake 7 and/or a state of the service brake 6. Inparticular, the unlocking part 29 may be coupled to a switchmechanically connected to that part 29 and having a first position and asecond position selected according to the position of the unlocking part29.

The service brake 6 is disposed in the body 2 and is configured to acton one or more braking members 35 of the rail vehicle via the brakinglinkage 4. The braking member 35 of the vehicle may comprise a brakedisk (here viewed from above) mounted for example on a rail vehicle axle36, or directly on the wheel to brake.

The braking linkage 4 is provided with a device 5 having linings whichis provided to apply forces on the brake disk 35 when the linkage 4 isactuated. This device 5 here comprises two lining mountings 37 to eachof which linings 38 are mechanically connected. In particular, twolinings 38 may be mounted on each lining mounting 37. Each lining 38 isprovided to be applied to contact the disk 35 to reduce its rotationalspeed and therefore that of the wheel to brake. The braking linkage 4here comprises levers 40, for example that are substantially deformable.In the described example, each lever 40 is provided with an upperportion and with a lower portion which are joined and which extend fromthe service and parking brake to the device 5. Each portion of thelevers 40 may be jointed to a central connector 41 via two pivots 42.The upper portion of each lever 40 may be linked by a first end to arespective joint 44, 45.

The braking linkage 4 may receive the body 2 between the upper portionsof the deformable levers 40, at the location of the joints 44 and 45.The body 2 may be rotatably mounted on the joint 44 which is attached toan end of the thrust rod 9 whereas it may have a fixed mounting to thejoint 45, which is directly attached to that body 2. The lower portionof each lever 40 may be linked, at a second end which is an opposite endto its first end, to one of the lining mountings 37 at the location ofan attachment region 39 provided on the latter and which faces away fromthe linings 37. The braking linkage 4 may comprise a first fasteningmember 43 joined to the central connector 41 for the mounting of thatbraking linkage 4 on the rail vehicle; in order for the lining mountings37 to be situated on respective opposite sides of the brake disk 35 (orof the wheel of the rail vehicle). The coming towards each other of thejoints 44 and 45 may enable the lining mountings 37 to be moved apartfrom each other and that conversely, the separation of those joints 44and 45 may enable the lining mountings 37 to be to clamped onto thebrake disk 35 (or onto the rail vehicle wheel).

The control and actuation unit 3 is connected to the service brakepressure chamber 13 via the first supply pipe 72 to which it isconnected. This unit 3 is connected to the parking brake pressurechamber 25 via the second supply pipe 71 to which it is connected. Thisunit 3 is supplied with pneumatic agents by a main pipe 70 which passesgenerally along the rail vehicle. The unit 3 comprises system members(not shown in FIG. 1) which are configured to receive and processrepresentational information relative for example to operationalsettings of the rail vehicle, by a first electrical and/or pneumaticand/or manual type channel, denoted 50 in FIG. 1.

These system members are furthermore configured to receive and processrepresentational information relating to parameters of use of the railvehicle, by a second channel of electrical and/or pneumatic and/ormanual type, which is denoted 60 in FIG. 1. These system members may forexample be formed by pneumatic relays and/or solenoids and/or pressureswitches and/or sensors and/or pressure reducing valves and/orelectrical relays and/or electronic cards and/or central processingunits or microprocessors, and/or random access memory componentscomprising registers adapted to record variables of the parameterscreated and modified during the execution of programs, and/orcommunication interfaces configured to send and receive data, and/orinternal storage members, such as hard disks, able in particular tostore the executable code of programs enabling the management of theservice and parking brakes 6 and 7. The control and actuation unit 3 maybe associated with one or more braking linkages of the vehicle.

FIG. 2 very diagrammatically shows the vehicle 48 provided with an axleforming a mounting 49 to which the system 1 is mechanically connected,via for example a second fastening member 47 which links the body 2 tothe mounting 49. The system 1 may comprise at least one forcetransmission link member 50 also mechanically connected at a first endto the mounting 49 of the vehicle 48 and at a second end, which is anopposite end to said first end, to said to the lining mounting 37, inimmediate proximity to said attachment region 39 of the lever 40. Thelining mounting 37 here faces opposite a face of the disk 35 mounted onits axle shaft 36 of the vehicle 48.

A description will now be given in more detail, with reference to FIGS.3 to 16, of the device 5 and of the arrangement of the levers 40 inrelation to the device 5, in accordance with several embodiments. FIGS.3 to 6 illustrate a first version of a first embodiment. The device 5faces opposite the brake disk 35. The device 5, comprising a liningmounting 37 and lining 38, has a longitudinal general orientation and atransverse general orientation. A longitudinal central axis 52 and atransverse central axis 51 are illustrated. They correspond to themedian axes of the brake disk 35 and, in the position illustrated inFIG. 3, respectively the transverse central axis 51 furthermorecorresponds to a transverse central axis of the device 3.

The lever 40 is mechanically connected to the lining mounting 37 via theattachment regions 39. The attachment regions 39 are located at most atapproximately 35 mm from the transverse central axis 51 of the device 5.This means that the distances E shown in FIG. 3 are each at most equalto 35 mm. Here, the attachment regions 39 are located on opposite sidesof the transverse central axis 51 and thus, at most, extend overapproximately 70 mm in the direction of the longitudinal generalorientation. More generally, the attachment region or regions 39 may belocated between approximately 0 and approximately 35 mm from thetransverse central axis 51 and may extend in a longitudinal generalorientation and over a length comprised between approximately 15 mm andapproximately 70 mm.

In the described example, the attachment regions 39 extend interruptedlyon opposite sides of the transverse central axis 51. In other words, theattachment regions 39 are distinct. As a variant, the attachment regionmay extend uninterruptedly on opposite sides of the transverse centralaxis 51. A longitudinal force application axis 53 is illustrated in finechain line, while a longitudinal holding axis 54 is illustrated in thickchain line.

The longitudinal force application axis 53 is the one passing throughthe attachment regions 39 of the lining mounting 37, which regionsenable the mechanical connection of the levers 40, while thelongitudinal holding axis 54 is slightly offset relative to thelongitudinal force application axis 53 and corresponds to the region forfastening the linings 53 onto the lining mounting 38.

The loads applied by the lever 40 of the braking linkage 4 on the device5 of that linkage 4 to place it in contact with the brake disk 35 arethus substantially centered on the lining mounting 37. Since theattachment regions 39 of the lever 40 on the lining mounting 37 areclose to the central transverse axis 51, this enables the liningmountings 37 to have a degree of freedom when it transmits forces to thebrake disk 35. In the described example, the device 5 comprises at leasttwo bearing regions 60 on the brake disk 35 and at least one set backregion 61 located between the two bearing regions 60.

More generally, the device may comprise a plurality of bearing regionsbetween which are formed set back regions. The bearing and set backregions 60, 61 succeed each other in the direction of the longitudinalgeneral orientation of the device 5. The two bearing regions 60 and theset back region 61 are provided here on a face of the lining mounting37, which is an opposite face to that on which are formed the attachmentregions 39. Each of the two bearing regions 60 is provided here so as tobe located facing opposite a respective lining 38.

This is shown in FIGS. 6 and 7 in which can be seen the bearing regions60 provided on the lining mounting 37 and in which can also be seenfavored contact regions 65 provided on the linings 38, whichrespectively correspond to the bearing regions 60. It will be noted thatthe bearing regions may be formed by protrusions on the lining mountingsand/or that the set back region may be formed by recesses in the liningmountings. The bearing regions and the set back regions are thus locatedin planes that are offset. In the described example, the bearing regions60 and the set back region 61 extend fully along the transverse generalorientation of the device 5.

Furthermore, the bearing regions 60 and the set back region 61 areformed here substantially symmetrically relative to the transversecentral axis 51. The device 5 and the braking linkage 4 which comes intocontact with the brake disk 35 is thus provided with a bearing surfacereferred to as discontinuous, with only the bearing regions 60 enablingforces to be transmitted to the brake disk 35. This enables thetransmission of the forces to the brake disk 35 to be distributed.

FIGS. 7 to 9 illustrate a second version. The difference compared withthe preceding version is that the bearing regions 60 are closer to eachother and to the transverse central axis 51, and the set back region 61is more limited. This results in the favored contact regions 65 providedon the linings 38 and which respectively correspond to the bearingregions 60 are also closer to each other and to the transverse centralaxis 51. The attachment regions 39 are identical to those describedabove.

FIGS. 10 and 11 are similar views to those of FIGS. 8 and 9, except thatthe bearing regions 60 and the set back region 61 do not extend fullyalong the transverse general orientation of the device 5. On thecontrary, the bearing regions 60 and the set back region 61 extend onlypartly along the transverse general orientation of the device 5. Thesame thus applies for the favored contact regions 65 provided on thelinings 38 and which respectively correspond to the bearing regions 60.In the example described, the bearing regions 60 and thus the favoredcontact regions 65 are situated rather towards the outside of the brakedisk 35.

FIGS. 12 and 13 are similar views to those of FIGS. 10 and 11, with thebearing regions 60 and the set back region 61 extending only partlyalong the transverse general orientation of the device 5, and rathertowards the inside of the brake disk 35. The same thus applies for thefavored contact regions 65 provided on the linings 38 and whichrespectively correspond to the bearing regions 60 and which are rathertowards the inside of the brake disk 35. In the example described, thebearing regions 60 and thus the favored contact regions 65 are situatedrather towards the outside of the brake disk 35.

FIGS. 14 to 17 illustrate a first version of a second embodiment. Thedevice 5 differs from those described above in that the lever 40 ismechanically connected to the lining mounting 37 via a single attachmentregion 39. The attachment region 39 is at the location of the transversecentral axis 51 of the device 5 and extends slightly on opposite sidesof that axis 51. For example, the attachment region extends onlyapproximately 10 mm to approximately 20 mm on opposite sides of thetransverse central axis 51. This means that the distance E shown in FIG.10 is at most equal to approximately 40 mm, in the direction of thelongitudinal general orientation. More generally, such a singleattachment region may extend in a longitudinal general orientation andover a length comprised between approximately 15 mm and approximately 70mm. The single attachment region 39 here extends uninterruptedly onopposite sides of the transverse central axis 51.

The loads applied by the lever 40 of the braking linkage 4 on the device5 of that linkage 4 to place it in contact with the brake disk 35 arethus substantially centered on the lining mounting 37. Since theattachment region 39 of the lever 40 on the lining mounting 37 is at thelocation of the central transverse axis 51, this enables the liningmountings 37 to have a degree of freedom when it transmits forces to thebrake disk 35. In the described example, the device 5 comprises at leasttwo bearing regions 60 on the brake disk 35 and at least one set backregion 61 located between the two bearing regions 60. The bearing andset back regions 60, 61 succeed in the direction of the longitudinalgeneral orientation of the device 5 and are identical to that of thedevice illustrated in FIGS. 3 to 6.

The two bearing regions 60 and the set back region 61 are provided hereon a face of the lining mounting 37, which is an opposite face to thaton which are formed the attachment regions 39, and each of the twobearing regions 60 is provided here so as to be located facing oppositea respective lining 38. Favored contact regions 65 are thus provided onthe linings 38, which respectively correspond to the bearing regions 60.The bearing regions 60 and the set back region 61 extend fully along thetransverse general orientation of the device 5, and are provided heresubstantially symmetrically relative to the transverse central axis 51.

The device 5 and the braking linkage 4 which comes into contact with thebrake disk 35 is thus provided with a bearing surface referred to asdiscontinuous, with only the bearing regions 60 enabling forces to betransmitted to the brake disk 35. This enables the transmission of theforces to the brake disk 35 to be distributed.

FIG. 18 is a similar view to that of FIG. 14, with addition of the forcetransmission link member 50 visible very diagrammatically in FIG. 2. Theforce transmission link member 50 is mechanically connected at its firstend to the mounting 49 of the vehicle and at a second end, which is anopposite end to its first end, to the lining mounting 37, and inimmediate proximity to the single attachment region 39 of the lever 40on that same lining mounting 37. The force transmission link member 50may be mechanically connected by pivotal connections 70, 75 respectivelyto the mounting 49 of the vehicle and to the lining mounting 37. Sincethe attachment regions 39 of the lever 40 on the lining mounting 37 areclose to and/or are centered on the transverse central axis 51 of thedevice 5, the pivotal connection 75 which connects the forcetransmission link member 50 to the lining mounting 37 is also at alocation close to that same transverse central axis 51, thereby limitingthe distance D shown in FIGS. 17 to 19. This in particular makes itpossible to have an especially compact system 1.

FIG. 19 shows the same force transmission link member 50 mechanicallyconnected to a lining mounting 37 of a device 5 similar to thatdescribed with reference to FIG. 15, with bearing regions 60 and a setback region 61 provided on the lining mounting 37, and with a singleattachment region 39 of the lever 40 on the lining mounting 37.

FIG. 20 shows very diagrammatically the force transmission link member50 mechanically connected to the lining mounting 37 of a device 5 quiteclose to those described above, but of which the bearing region 60 isformed here with steps. In other words, the bearing region 60 comprisesdifferent bearing portions 63 and 64 offset to a greater or lesserextent relative to the adjacent set back region 61. In particular, thebearing portion 63 forms what is designated an augmented-bearing region.

In variants not illustrated, the lining-mounting may comprise one ormore set back regions extending for approximately 100 mm toapproximately 300 mm from the transverse central axis of said device.The set back region or regions may be formed by cavities having a depthcomprised for example between approximately 0.1 mm and approximately 0.5mm.

According to a first example embodiment, the lining-mounting cancomprise a single set back region extending for approximately 180 mm (orfor 90 mm on opposite sides of the transverse axis), and having a cavityof approximately 0.2 mm; the rest of the lining-mounting overall formingone or more bearing regions.

According to a second example embodiment, the lining-mounting cancomprise a first set back region extending for approximately 120 mm (orfor 60 mm on opposite sides of the transverse axis), and having a cavityof approximately 0.3 mm, next the second set back regions either do ordo not immediately succeed the first set back region, each extending forapproximately 60 mm and having a cavity of approximately 0.15 mm; therest of the lining-mounting overall forming one or more bearing regions.

According to a third example embodiment, the lining-mounting cancomprise a first set back region extending for approximately 120 mm (orfor 60 mm on opposite sides of the transverse axis), and having a cavityof approximately 0.35 mm, next the second set back regions either do ordo not immediately succeed the first set back region, each extending forapproximately 60 mm and having a cavity of approximately 0.2 mm; therest of the lining-mounting overall forming one or more bearing regions.

Such arrangements of the set back regions make it possible to distributethe transmission of the forces over the braking member.

Other variants not illustrated are described below.

The force transmission link member may have an added functionalclearance at least at its second end where it is connected to the liningmounting by its pivotal connection. In particular, the forcetransmission link member may be connected via a rotary joint to thelining mounting or instead via a pivotal shaft pivoting in an apertureof considerably greater diameter than that of the pivotal shaft, or inan oblong aperture. For example, an axis of the force transmission linkmember may be angularly offset to enable the device, including thelining mounting and the linings, to self-tilt to maintain optimumapplication of the braking force while making it possible to send theforces to the vehicle mounting. This in addition to makes it possible tolimit the wear of the linings 38 obliquely, despite the deformationswhich for example the brake disk 35 may undergo.

The force transmission link member may be substantially L-shaped, orS-shaped, with the pivotal connections being respectively to themounting of the vehicle and to the lining mounting 37. The forcetransmission link member may extend substantially in a same plane asthat in which said lever extends. Such an arrangement is particularlycompact and enables a maximum travel of the lining mounting relative tothe mounting, thanks the L-shaped or S-shaped force transmission linkmember which does not cause hindrance by the movement of the liningmounting.

The bearing regions and/or the set back region may be provided in thelinings rather than in the lining mountings. Some bearing and/or setback regions may extend fully along the transverse general orientation,while other of these regions may extend only partly. The bearing and setback regions are not provided substantially symmetrically relative tothe transverse central axis. A single lining, rather than two linings,is mounted on each of the lining mountings, or, on the contrary, morethan two linings are mounted on each of the lining mountings.

The force transmission link member may be mechanically connected to thevehicle mounting, directly or by an intermediate connecting part. Theforce transmission link member may be H-shaped, or Y-shaped, it beingpossible for this to be inverted, or for instance I-shaped, rather thanL-shaped or S-shaped.

The rail vehicle braking system may be different from that describedabove in that it may concern only a service brake, or concern only aparking brake, and in that the mechanism may have springs as has forexample been described in document EP 2 154 040.

More generally, the invention is not limited to the examples describedand illustrated.

1. A vehicle braking system, comprising: a braking linkage; one or moreof a service brake or a parking brake configured to act on at least onebraking member of a vehicle via the braking linkage, the braking linkageprovided with at least one device having at least one lining mountingand at least one lining mechanically connected to the at least onelining mounting, the at least one device comprising plural bearingregions for bearing on the at least one braking member and at least oneset back region located between the bearing regions.
 2. The vehiclebraking system according to claim 1, further comprising at least twolinings mechanically connected to the at least one lining mounting, atleast one of the bearing regions located facing opposite a respectiveone of the at least one lining.
 3. The vehicle braking system accordingto claim 1, wherein the bearing regions and the at least one set backregion are provided on the at least one lining mounting.
 4. The vehiclebraking system according to claim 1, wherein the bearing regions and theat least one set back region are provided on the at least one lining. 5.The vehicle braking system according to claim 1, wherein the at leastone device comprises two or more of the bearing regions between whichthe at least one set back region is formed.
 6. The vehicle brakingsystem according to claim 1, wherein one or more of the at least onelining mounting or the at least one lining have a longitudinal generalorientation and a transverse general orientation, with the bearingregions and the at least one set back region succeed each other in thelongitudinal general orientation.
 7. The vehicle braking systemaccording to claim 6, wherein one or more of (a) at least one of thebearing regions or (b) the at least one set back region fully extends oronly partly extends along the transverse general orientation.
 8. Thevehicle braking system according to claim 1, wherein the bearing regionsand the at least one set back region are provided substantiallysymmetrically relative to a transverse central axis of the at least onedevice.
 9. The vehicle braking system according to claim 1, wherein thebraking linkage is provided with at least one lever extending from theone or more of the service brake or the parking brake to the at leastone device, the at least one lever mechanically connected to the atleast one lining mounting on an attachment region thereof that islocated away from the at least one lining and which is at most 35millimeters (mm) from a transverse central axis of the at least onedevice.
 10. The vehicle braking system according to claim 9, wherein theattachment region is located between approximately 0 and 35 mm from thetransverse central axis of the at least one device.
 11. The vehiclebraking system according to claim 9, wherein the attachment regionextends in a longitudinal general orientation of the at least one deviceand over a length between approximately 15 mm and approximately 75 mm.12. The vehicle braking system according to claim 9, wherein theattachment region uninterruptedly extends on opposite sides of thetransverse central axis of the at least one device.
 13. The vehiclebraking system according to claim 9, wherein the attachment regioninterruptedly extends on opposite sides of the transverse central axisof the at least one device.
 14. The vehicle braking system according toclaim 13, further comprising at least one force transmission link membermechanically connected at a first end to a mounting of the vehicle andat an opposite second end to the at least one lining mounting inimmediate proximity to the attachment region of the at least one lever.15. A vehicle comprising at least one braking member and at least onevehicle braking system according to claim 1 which is configured to acton the at least one braking member.